The human visual system can perceive 135° vertically and 160° horizontally, but can perceive fine detail only within about a 5° central circle. Outside this visual field, resolving power falls dramatically. Because the human eye can be redirected quickly to a point of interest, people are rarely aware of the fact that most of the visual field is a blur. However, according to current computer graphics techniques, every region of an image is rendered at equal resolution because the viewer's gaze is unknown. This is wasteful because computer graphics processing is computationally expensive.